This issue matters to people not because the U.S. gov't is backstopping losses of GSEs, but because securitized debt instruments spread highly levered risk to a host of financial institutions that were not contractually involved in the originator's risk decisions. This was a primary cause of a recession that affected the world economy.

Systemic risk is the term, and it is a negative externality that affects the lowliest gas station attendant to the Lehman proprietary trader.

Besides, TARP came out OK -- your tax payers made a profit on it.